Stroke

Definition

When the blood supply to a part of the brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients, a stroke occurs, and brain cells begin to die within a few minutes.

Urgent treatment of a stroke is crucial as stroke is a medical emergency. Potential stroke complications and damage to the brain can be minimized by early treatment.

Fortunately, strokes can be treated. The decline of deaths caused by strokes may be due to improvements in the control of major risk factors for stroke, which include high cholesterol, smoking and high blood pressure.

Work Group:

Prepared by: Scientific Section

Symptoms, Causes

Symptoms:

The following signs and symptoms may indicate that a person is having a stroke:

Headache:
Sometimes, a sudden, severe "bolt out of the blue" headache or an unusual headache that may be accompanied by altered consciousness, vomiting, pain between the eyes, facial pain or a stiff neck, may indicate that a person is having a stroke.

Paralysis or numbness on one side of the body:
A person may experience sudden numbness, paralysis or weakness on one side of the body when having a stroke. Someone may be having a stroke if he\she raises both arms over the head at the same time and one arm begins to fall.

Trouble with speaking:
A person may slur his\her speech or may not be able to come up with words to explain what is happening (aphasia) when having a stroke. A person may be having a stroke if he/she has trouble repeating a simple sentence.

Trouble with seeing:
A person may suddenly have blurred or blackened vision or may see double when having a stroke.

Trouble with walking:
A person may stumble or have sudden dizziness, loss of coordination or loss of balance when having a stroke.

A stroke gives no warning for most people. However, a transient ischemic attack (TIA) is one possible sign of an impending stroke, and this condition is a temporary interruption of blood flow to a part of the brain, which has the same signs and symptoms of a stroke, but they last for a shorter period; usually several minutes to 24 hours, and then, without leaving apparent permanent effects, they disappear. A person may have more than one TIA, and the recurrent signs and symptoms may be different or similar.

Stroke is much more likely to happen to people who have had a TIA than those who haven't. So TIA may indicate that a person is at risk of a full-blown stroke.

One should get urgent medical help when noticing any signs or symptoms of a stroke or TIA. TIA is an important warning sign and a chance to take steps that may prevent a stroke, though it may seem like a passing event.

While waiting for an ambulance, one should watch the patient that appears to be having a stroke carefully. Additional actions may be needed in the following situations:

-The patient shouldn’t eat or drink anything
-Beginning mouth-to-mouth resuscitation if the patient stops breathing
-To prevent choking, turning the patient’s head to the side if vomiting occurs.

When it comes to treating a stroke or TIA, every minute counts. A stroke is sometimes referred to as “brain attack” to convey that quick care is important, just like a heart attack. The longer a stroke goes untreated, the greater the damage and potential disability; so one shouldn’t wait to see if the signs and symptoms go away. After signs and symptoms begin, how soon the patient is seen by a doctor in a hospital emergency room is the thing that determines the success of most stroke treatments.

Causes:

When there is a problem with the amount of blood in a person’s brain, a stroke occurs. Too little blood in the brain is the cause of the main type of stroke, called ischemic stroke. On the other hand, too much blood within the skull is the cause of the other type of stroke called hemorrhagic stroke.

ISCHEMIC STROKE:

Ischemic strokes make up about 80% of strokes. Causing severely reduced blood flow (ischemia), they occur when the arteries to the brain are narrowed or blocked, depriving the brain cells of oxygen and nutrients; and within minutes, cells may begin to die. Here are the most common types of ischemic strokes:

Thrombotic stroke:
When a blood clot (thrombus) forms in one of the arteries that supply blood to the brain, this type of stroke occurs. In the areas that are damaged by atherosclerosis, which is a disease in which the arteries are clogged by fatty deposits (plaques), is where a clot usually forms. Within one of the two carotid arteries of the neck that carry blood to the brain, as well as in other arteries of the neck or brain, this process can occur.

Embolic stroke:
When a blood clot or other particle forms in a blood vessel away from the brain, usually in the heart, and is swept through the bloodstream to lodge in narrower brain arteries, an embolic stroke occurs. An embolus is the name of this type of blood clot. Irregular beating in the heart's two upper chambers (atrial fibrillation) is usually the cause. Poor blood flow and the formation of a blood clot may be caused by this abnormal heart rhythm.

HEMORRHAGIC STROKE:

The medical word for bleeding is "hemorrhage". When a blood vessel in the brain leaks or ruptures, a hemorrhagic stroke occurs. Including uncontrolled high blood pressure (hypertension) and weak spots in the blood vessel walls (aneurysms), a number of conditions that affect the blood vessels can be the cause of hemorrhages. The rupture of an arteriovenous malformation (AVM), which is an abnormal tangle of thin-walled blood vessels present at birth, is a less common cause of hemorrhage. Here are the two types of hemorrhagic stroke:

Intracerebral hemorrhage:
A blood vessel in the brain bursts in this type of stroke and spills into the surrounding brain tissue damaging cells. Brain cells that are beyond the leak are damaged as well because they are deprived of blood. The most common cause of this type of hemorrhagic stroke is high blood pressure. Small arteries inside the brain may become brittle and susceptible to cracking and rupture and this is caused by high blood pressure over time.

Subarachnoid hemorrhage:
Bleeding starts in a large artery on or near the surface of the brain and spills into the space between the surfaces of the brain and the skull in this type of stroke. A sudden, severe "thunderclap" headache often signals this type of hemorrhage. The rupture of an aneurysm, which can develop with age or be genetically inherited, is the most common cause of this type of stroke. Causing brain cell damage by further limiting blood flow to parts of the brain, the blood vessels in the brain may widen and narrow erratically (vasospasm) after the hemorrhage.

TRANSIENT ISCHEMIC ATTACK (TIA) AND STROKE:

The brief episode of symptoms similar to those one would experience during a stroke is referred to as transient ischemic attack (TIA, or ministroke). Temporary decrease in blood supply to part of the brain is the cause of a transient ischemic attack. Most attacks last just a few minutes.

The cause of TIA is the same as that of ischemic stroke. A clot blocks the blood supply to part of the brain in ischemic strokes, which are the most common type of stroke. However, a TIA doesn't leave lasting effects to the brain compared with a stroke, which involves a more prolonged lack of blood supply and causes some permanent damage to the brain tissue. However, one is at a greater risk of a full-blown stroke that could cause more permanent damage when having had a TIA, which means that there's likely a blocked or narrowed artery leading to his\her brain. One should get immediate emergency medical treatment and make sure that his\her regular physician knows about it in the case of having a TIA.

One’s risk of a stroke may increase due to several factors, a number of which can increase the chances of having a heart attack as well. The risk factors of stroke include:

-A previous stroke or TIA
-High levels of homocystein in the blood, which is an amino acid
-High blood pressure; a systolic blood pressure of 10 millimeters of mercury (mm H) or higher, or a diastolic pressure of 90 mm Hg or higher
-Family history of a stroke, heart attack or TIA
-Smoking cigarettes
-High cholesterol; a total cholesterol level of 200 milligrams per deciliter (mg/dL), or 5.2 mmol/L, or higher
-Being 55 or older
-Using birth control pills or other hormone therapy
-Diabetes
-A cardiovascular disease, including a heart defect, heart infection, abnormal heart rhythm or heart failure.
-Obesity; a body mass index of 30 or higher

Heavy or binge drinking and the use of illicit drugs such as cocaine are included in the factors that can increase someone’s risk of stroke.

Strokes are more likely to occur in black people than in people of other races. Women die more often of strokes than men, although men and women have strokes at about the same rate.

Complications

Complications:

Temporary or permanent disabilities can sometimes be caused by a stroke, depending on how long the brain suffers a lack of blood flow. Based on what part of the brain was affected, complications of stroke differ and they include:

Pain:
Numbness, pain or other strange sensations in parts of the body affected by stroke, may be experienced by some people who have a stroke. For instance, one may have an uncomfortable tingling sensation in the left arm if the stroke causes the patient to lose feeling in that arm. One may be sensitive to temperature changes as well, extreme cold in particular. Central pain syndrome (CPS) or central stroke pain is the name of this condition. There are few medications to treat CPS because the pain is caused by a problem in the brain instead of a physical injury, though this complication may improve with time.

Difficulty talking or swallowing:
Making it difficult to talk, swallow or eat, a stroke may cause a person to have less control over the way the muscles in the mouth move. In some cases, a stroke may cause aphasia, a condition in which a person has difficulty expressing thoughts through language, resulting in the patient’s difficulty speaking. This disability can be improved by therapy with a speech and language pathologist.

Paralysis or loss of muscle movement:
A person may become paralyzed on one side of the body or lose control of certain muscles, such as those on one side of the face, as a result of a lack of blood flow to the brain. This patient may see improvement in muscle movement or paralysis with physical therapy.

Memory loss or troubles with understanding: Having some memory loss is common in people who suffer strokes. Difficulty understanding concepts may develop in others. However, with rehabilitation therapies, this complication may improve.

To help People who have a stroke with their grooming needs and daily chores after a stroke, they may need a caretaker as they may lose the ability to care for themselves, and they may become withdrawn and less social as well.

The success of treating the complications mentioned above varies from one person to another, as with any brain injury.

Treatments:

It's important to get prompt medical treatment for stroke. The type of stroke will determine the treatment.

ISCHEMIC STROKE:

Doctors must quickly restore blood flow to the patient's brain to treat an ischemic stroke.

Emergency treatment with medications:Within three hours, the therapy with clot-busting drugs must start. The amount of complications that result from the stroke may be reduced and the patient's chances of survival improved by quick treatment. The patient may be given the following:

-Acetylsalicylic acid: The best-proven immediate treatment after a stroke to reduce the likelihood of having another stroke is aspirin. It's likely that the patient will be given a dose of aspirin in the emergency room. However, this dose may vary, and the patient should make a note in his\her purse or wallet on an emergency medical card, so that the doctors will know if he/she has already had some aspirin. The patient shouldn’t take aspirin before going to the hospital, because the bleeding may become worse if the patient is having a hemorrhagic stroke. Other blood-thinning drugs such as warfarin aren't as commonly used as aspirin, though they may be given as well.

-Tissue plasminogen activator: An injection of tissue plasminogen activator (TPA) can be helpful for some people who are having a stroke. TPA is a potent clot-busting drug that helps some people who have had stroke to recover fully. However, the drug can only be given in situations in which doctors are certain that giving TPA will not worsen bleeding in the brain, and it can only be given to patients within a three-hour window of the stroke occurring. In the cases of people who are having a hemorrhagic stroke, TPA can't be given.

Surgical and other procedures:
A procedure to open up an artery that's moderately to severely narrowed by plaques may be recommended. These procedures may include:

-Carotid endarterectomy: The surgeon removes plaques in this procedure that block the carotid arteries that run up both sides of the neck to the brain. The blocked artery is opened, the plaques are removed and the artery is closed. A person’s risk of ischemic stroke may be reduced by this procedure. Although surgeons now place filters (distal protection devices) at strategic points in the patient’s bloodstream to "catch" any material that may break free during the procedure by releasing a blood clot or fatty debris, but a carotid endarterectomy itself can trigger a stroke or heart attack, in addition to the usual risks associated with any surgery.

-Angioplasty and stents: The inside of an artery leading to the brain, usually the carotid artery, can be widened by angioplasty, which is used less commonly than carotid endarterectomy. A balloon-tipped catheter is maneuvered into the obstructed area of the artery in this procedure. The balloon is inflated to compressing the plaques against the artery walls. To prevent recurrent narrowing, a metallic mesh tube (stent) is usually left in the artery. For some people who've had a stroke or a transient ischemic attack (TIA) but can't undergo surgery, angioplasty and stenting of carotid arteries may be an appropriate stroke prevention option. Intracranial stenting is similar to stenting the carotid arteries. A catheter is threaded through the arteries and into the brain using a small incision in the groin. In some cases, angioplasty is not used before stent placement, and in other cases, angioplasty is used to widen the affected area first.

HEMORRHAGIC STROKE:

To treat a hemorrhagic stroke or prevent another one, surgery may be used. Aneurysm clipping and arteriovenous malformation (AVM) removal, which are the most common procedures, carry some risks. If the patient is at high risk of spontaneous aneurysm or AVM rupture, one of these procedures may be recommended:

-Surgical AVM removal: If an AVM is located deep within the brain or if it's too large, removing it is not always possible. Lowering the overall risk of hemorrhagic stroke, the risk of rupture can be eliminated by surgical removal of a smaller AVM from a more accessible portion of the brain.

-Aneurysm clipping: Isolating the aneurysm from the circulation of the artery to which it's attached, a tiny clamp is placed at the base of it. This can prevent re-bleeding of an aneurysm that has recently hemorrhaged, or it can keep the aneurysm from bursting. This clip permanently stays in place.

-Coiling (aneurysm embolization): A catheter is maneuvered into the aneurysm in an embolization procedure, and a tiny coil is positioned inside the aneurysm after it has been pushed through the catheter. Causing clotting and sealing the aneurysm off from connecting arteries, the coil fills the aneurysm.

STROKE RECOVERY AND REHABILITATION:

Encouragement and early treatment are important, so stroke survivors who go home to a healthy spouse or other companion are more likely to become independent and productive again.

The amount of damaged tissue and the area of the brain involved are the things that determine recovery and rehabilitation. Sensation and movement on the left side of the body may be affected by harm to the right side of the brain. Movement on the right side of the body may be affected by damage to brain tissue on the left side, in a damage that may cause speech and language disorders as well. People who've had a stroke may have problems with swallowing, balancing and hearing, breathing, loss of vision and bladder or bowel function.

Stroke recovery differs in each person. The team that will the patient in his\her recovery could include the following depending on what complications the patient has:

Helping the patient recover as much of his/her independence and functioning as possible is the purpose of stroke rehabilitation. Relearning skills the patient may have lost, such as communicating or walking, is involved in much of stroke rehabilitation.